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Three Cases of Low Chiasma Frequency Associated with Infertility in Man

2009; Wiley; Volume: 8; Issue: 4 Linguagem: Inglês

10.1111/j.1439-0272.1976.tb01657.x

1439-0272

C. Templado, S. Marina, J. Egozcue,

Seed Germination and Physiology

Three new cases of low chiasma frequency in infertile men are described. In the first case, all cells showed abnormal diakineses; in the second, 20% of the diakineses were desynaptic, while the remaining 80% were normal; in the third, all diakineses were desynaptic and showed chromosome fragmentation. The possible mechanisms leading to asynapsis, desynapsis or precocious chiasma terminalization are discussed.3 cases of low chiasma frequency associated with infertility in men are reported. Patients were 30-, 35-, and 38-years-old, respectively, and had normal secondary sex characteristics. Meiotic chromosomes were studied in testicular biopsies of 2 and in the semen of 1 patient. Semen analysis in the 1st patient revealed azoospermia with meiotic arrest at the 2nd spermatocyte level. Bivalent forming of 2 chiasmata were seen only occasionally. In the 2nd patient, oligo-astheno-teratozoospermia with piriform spermatozoa was revealed. Incomplete meiotic arrest was apparent at the spermatid level. 80% of the diakinetic cells were normal but there was an extremely low chiasma frequency in 20% of the 38 diakineses observed. The morphology was different than in the 1st case; chromosomes were more tightly coiled, bivalent frequently had 2 and 3 chiasmata and precocious separation of the small bivalents into univalents was more obvious. Semen analysis of the 3rd patient revealed poly-astheno-teratozoospermia. Meiotic preparations contained an extremely high number of metaphase 1 figures. Pairing abnormalities were present from early prophases 1. In metaphase 1 figures studied, chromosomal bodies appeared highly disorganized and fragmented. However, 1 or even 2 chiasmata were present. It is suggested that the anomalies seen result from asynapsis. Abnormal coiling may also be involved as might a defective regulatory mechanism of chiasma terminalization.